Metal sulfides, such as MoS2, are widely investigated in lithium–sulfur (Li–S) batteries to suppress the shuttling of lithium polysulfides (LiPSs) due to their chemical adsorption ability and catalytic activity. However, their relatively low conductivity and activity limit the LiPS conversion kinetics. Herein, the Co-doped MoS2 is proposed to accelerate the catalytic conversion of LiPS as the Co doping can promote the transition from semiconducting 2H phase to metallic 1T phase and introduce the sulfur vacancies in MoS2. A one-step hydrothermal process is used to prepare such a Co-doped MoS2 with more 1T phase and rich sulfur vacancies, which enhances the electron transfer and catalytic activity, thus effectively improving the LiPS adsorption and conversion kinetics. The cathode using the three-dimensional graphene monolith loaded with Co-doped MoS2 catalyst as the sulfur host shows a high rate capability and long cycling stability. A high capacity of 941 mAh g–1 at 2 C and a low capacity fading of 0.029% per cycle at 1 C over 1000 cycles are achieved, suggesting the effectively suppressed LiPS shuttling and improved sulfur utilization. Good cyclic stability is also maintained under a high sulfur loading indicating the doping is an effective way to optimize the metal sulfide catalysts in Li–S batteries.

No abstract

No abstract

gent wearable medical devices (IWMDs) has advanced rapidly, with research emphasis on physiological/pathological factors inducing biosensing and active delivery of therapeutic agents in an ondemand manner. [1] IWMDs constitute a vast array of wearable types, such as wrist bands, smart contact lenses, smart patches, and electronic textiles, which are used to measure biophysical or biochemical signals and, most recently, to achieve therapeutic interference by establishing microenvironmental detection-delivery feedback cycles. Accordingly, IWMDs have become critical components in achieving personalized healthcare and precision medicine. [2] Such devices can provide predictive bio-analysis and offer timely treatment intervention, improving drug efficacy, overcoming the potential dangers due to delayed treatment, and expanding the flexibility of drug use in time and space.For biodetection and monitoring, wearable biosensing devices (WBDs) have been developed to detect many physiological features such as mechanical deformations, electrocardiogram (ECG) signals, body temperature, [3][4][5] and biochemical components such as glucose, calcium ions, and lactate. [6][7][8] For a long time, efforts have been made to advance WBDs by tracking single analytes to multiple analytes. Previous reviews have described several types of representative wearable sensors for healthcare monitoring. [9] For drug delivery, transdermal/topical wearable delivery devices (WDDs) are advantageous over oral and injection delivery modalities in terms of flexibility and scalability and have been utilized to deliver therapeutic agents such as polypeptides, [10][11][12] polysaccharides, [13] small molecules, [14] and growth factors [15] continuously and responsively. Recent studies indicate that wearable transdermal patches constructed from responsive materials show great advantages and attractive prospects in application of WDDs. [16] Despite the considerable development of WBDs and WDDs, efforts are being made to combine them into a single system to provide both sensing and delivery services, for which IWMDs are expected to realize two core functions: identification of physiological/pathological markers and delivery of therapeutic agents. [17] As Figure 1 shows, IWMDs are defined as composite pieces of equipment that contain multiple subsystems, including embedded sensors, drug repositories, and their connecting attachments. In addition, some other components, The primary roles of precision medicine are to perform real-time examination, administer on-demand medication, and apply instruments continuously. However, most current therapeutic systems implement these processes separately, leading to treatment interruption and limited recovery in patients. Personalized healthcare and smart medical treatment have greatly promoted research on and development of biosensing and drug-delivery integrated systems, with intelligent wearable medical devices (IWMDs) as typical systems, which have received increasing attention because of their non-invasive and custom...

No abstract

Background: The shortage of donor corneas is a severe global issue, and hence the development of corneal alternatives is imperative and urgent. Although attempts to produce artificial cornea substitutes by tissue engineering have made some positive progress, many problems remain that hamper their clinical application worldwide. For example, the curvature of tissue-engineered cornea substitutes cannot be designed to fit the bulbus oculi of patients. Objective: To overcome these limitations, in this paper, we present a novel integrated three-dimensional (3D) bioprintingbased cornea substitute fabrication strategy to realize design, customized fabrication, and evaluation of multi-layer hollow structures with complicated surfaces. Methods: The key rationale for this method is to combine digital light processing (DLP) and extrusion bioprinting into an integrated 3D cornea bioprinting system. A designable and personalized corneal substitute was designed based on mathematical modelling and a computer tomography scan of a natural cornea. The printed corneal substitute was evaluated based on biomechanical analysis, weight, structural integrity, and fit. Results: The results revealed that the fabrication of high water content and highly transparent curved films with geometric features designed according to the natural human cornea can be achieved using a rapid, simple, and low-cost manufacturing process with a high repetition rate and quality. Conclusions: This study demonstrated the feasibility of customized design, analysis, and fabrication of a corneal substitute. The programmability of this method opens up the possibility of producing substitutes for other cornea-like shell structures with different scale and geometry features, such as the glomerulus, atrium, and oophoron.

No abstract

No abstract